This fine piece of engineering compacts to the size of a small suitcase and circumvents all known railway by-laws

At this time of year, there is much to be said for allowing plenty of flexibility in your travel plans - it could earn a profit. Many flights are overbooked, and if you are willing and able to take a later flight, you could find the airline offering a bribe to forgo your seat reservation.

Randeep Ramesh, our transport correspondent, has just returned from a weekend in Dublin. His return flight on British Midland cost pounds 120 - much of which was handed back to him. At Heathrow, the airline gave him pounds 50 in return for switching to a flight two hours later - and made the same offer on the inbound leg.

Independent reader Anne-Marie Williams, of Southend, was offered even more when she and her husband checked in for a United Airlines flight to San Francisco: "Passengers were being offered vouchers worth $600 [pounds 360] to transfer to the next flight, as ours was overbooked. We didn't feel able to take up the offer, because we had an onward flight to Las Vegas."

Then it all started to go badly wrong. The San Francisco flight was delayed by five hours, and made an unscheduled stop in Washington DC. The couple arrived in Las Vegas seven hours late: "Ironically, the 'later' flight which we had declined got in well ahead of ours. Had we known about the delay earlier, we certainly would have changed our flight."

Ms Williams asked United whether it would award compensation of $600 each, as originally offered. The airline responded with vouchers for $300, which Ms Williams has decided to accept. "The moral: before you decline an airline's bribe, make sure your appointed flight is on time."

You may recall last summer's tales of misery on ScotRail, with cyclists getting stranded in the Highlands because only one or two bikes are allowed on each train. According to Judy Griffiths, of Dewsbury, barriers to environmentally sensitive travel are spreading south.

Ms Griffiths promised her children that they would tackle part of the new Sustrans Hull-to-Harwich cycle route. "I went to the local station to book the tickets to Hull, to be told that only two cycles are allowed on any one train.

"The dilemma then was which child to leave standing alone on the platform for an hour. To compound the situation, they then told me that this lone child would not be eligible for a cheap ticket on the Family Railcard since we would not all be travelling on the same train."

All I can offer to Ms Griffiths is the solution I adopted after one run- in too many with ScotRail guards last summer: a Brompton folding bicycle. This fine piece of British engineering, made in Chiswick, West London, compacts to the size of a small suitcase and circumvents all known railway by-laws. It has also received an endorsement from an unexpected quarter: the Director of Corporate Affairs for ScotRail uses one to get to work.